So, I’m wandering my local grocery store and I’m beginning to notice just how much money I’m “saving” by carrying the store’s loyalty card in my wallet. I couldn’t snag pot roasts on the “2 for the price of 1″ deal without it. My block of Velveeta, which will eventually become part of a NCAA Final Four Nacho Slam Dunk Feast (by the way, I have Louisville winning the whole thing) would’ve cost an extra $1.75 without the card. The card even allowed me to pick up a good can of creamed corn with the green giant on it for a little less than the store brand.

By the time I made it past the tabloids and checked out Valerie Bertinelli’s new bikini body (hubba, hubba) on the cover of People, I had cut my bill down by at least $50 by using that handy-dandy little “rewards” card.

You might be thinking that’s the moral to this particular story: Get the card and use the card. The discounts add up.

It isn’t. It may be true, but the decision about using those cards is actually a little more complicated.

I know you love the supermarket and you’d like to consider you part of their extended family. There’s a helpful smile in every aisle and the guy at the meat counter treats you like you’re his favorite person in town. The bakery people slide you the occasional free cookie and the one older lady who runs a checkout line on weekends is a dead-ringer for Aunt Gertrude (only without the creepy moles).

This fun-loving bunch of your commercial amigos, however, isn’t shoving that little plastic card into your billfold because of love. It’s not about wanting to take care of you. It’s not a matter of wanting you to be able to put your kids through college. They give you the card (and the “savings”) because… Well, because it makes them a boatload of money.

First, the loyalty cards do encourage people to keep coming back to the same store. You keep going to the same place instead of trying that other market, in part, because you know you can “save” with your loyalty card.

Second, the card is a data source. Good research makes the corporate world go ’round and those cards provide a great deal of data about you and what you’re buying. It also gives them a good idea of how often you’re buying the stuff, what you’re willing to pay, what items you buy in tandem with one another, etc. The store can use that info to maximize its bottom line.

That’s a fair trade, right? You give up some personal spending data for them to use and they trim a little off the bill. Nothing wrong with that, is there?

It depends. It depends on how much personal data you really want to share with the corporate masterminds who run the card programs. It also depends on how you feel about the way the stores use the data.

There are organizations who are committed to getting rid of these loyalty programs because of the way the data is used. They argue that supplying the grocery store with all of that information in pursuit of a bargain can lead to:

Higher prices. The store figures out how badly it can beat you up before you just won’t buy something. Personally, I don’t have a problem with stores finding the point of price equilibrium, but some do.

Misleading “rewards”. The store will jack the prices up on certain items, using your card will only bring them back down to earth. It’s not really saving you anything over the competition. Meanwhile, it could be making life tougher for the poor or cardless.

Customer-base sculpting. Grocery stores make most of their profits from top-tier customers. Those folks toward the bottom of the socioeconomic ladder buy food, but they don’t by the high-margin stuff. As such, the stores are primarily interested in catering to those folks at the top and don’t really mind if they freeze out the poor altogether. This can have some serious social consequences, according to critics.

So, are you going to use that loyalty card? I’ll be honest with you. I’ll probably still pull it out when they run the “2 for the price of 1″ deals on expensive cuts of meat. In other cases, after reading what groups like CASPIAN have to say, I might just keep it in my wallet… At least until I have time to reall think this all through.